Observer-Driven LQR and FOLQR Control for Enhanced Stability of Underactuated 2-DOF Helicopter.

This study offers an empirical comparison of the Linear Quadratic Regulator (LQR) and Fractional Order LQR (FOLQR) controllers that were implemented on a two-degrees-of-freedom (2-DOF) Quanser Aero 2 helicopter platform. It employs both full and reduced-order observer designs to facilitate trajectory monitoring and stabilisation. The Aero 2 platform is dynamically modelled using Euler-Lagrange equations to develop a multi-input multi-output (MIMO) system. This system comprises two inputs and four state equations. In collaboration with observers, the LQR and FOLQR controllers approximate states that are not directly measurable by utilising the system model and available data. This procedure effectively overcomes the practical limitations of sensors. The enhanced performance of FOLQR in terms of tracking precision and stability has been depicted from the experimental results, showing real-time execution on the Aero 2 platform. This paper provides rigorous insights into control engineering and advanced observer-based control design for underactuated systems.